Northern Prairie Wildlife Research Center
Often called "ball cactus", Missouri pincushion cactus occurs in the southwestern quarter of North Dakota. Elsewhere, the plant ranges from Idaho to Texas.
The rounded stems or "balls" of this perennial plant have to carry on the photosynthesis, because there are no true leaves. These stems, which protrude part way through the prairie sod, may be found singly or branched into groups of up to a dozen. Numerous spine-bearing tubercles dot the plant. Unlike the common, magenta-flowered pincushion cactus found nearly throughout North Dakota, Missouri pincushion has yellow flowers. The flowers are about 2 inches wide. Fleshy, bright-red fruits mature seeds the following spring.
In North Dakota, Missouri pincushion cactus seems to thrive under the drier conditions caused by heavy grazing, but in the more arid parts of its range, more plants are usually seen where grazing is light or moderate.
This plant is, of course, a member of the cactus family (Cactaceae), the name derived from the Greek kaktos, a spiny plant of the Mediterranean. This is a large family with perhaps 1200 species that are almost entirely restricted to the Americas. The generic name Coryphantha means "top-flowered" in botanical Latin, in reference to the placement of the flower atop the stem. Missouriensis means "of Missouri," in reference to the River, not the State. This species was described for science in 1827 by the English horticulturist and ornithologist Robert Sweet (1783-1835). Sweet was monographer of the geranium family.